1. Field of the Invention
The present invention relates to a syringe and, more particularly, to a disposable safety syringe that can be disposed of and thrown away.
2. Description of the Related Art
A conventional safety syringe comprises a barrel, an inner tube mounted in the barrel and provided with a needle, a spring mounted on the inner tube and biased between the inner tube and the barrel, and a plunger movably mounted in the inner tube. However, the spring is made of metal to largely increase the cost of fabrication of the safety syringe. In addition, a user has to user his/her two hands to hold the barrel and to operate the spring so as to pull the inner tube from the barrel and to retract and hide the needle, thereby greatly causing inconvenience to the user.